Method of slitting a continuous strip of metal and article formed therefrom



United States Patent 11113,540,395

[72] lnventor Robert L. Skinner [56] References Cited South 3911111194191" UNITED STATES PATENTS [211 P 973,168 10/1910 Caswell 113/116 [22] F1led Feb. 18, 1969 1,494,410 5/1924 Bidle 29/159 [45] Patented Nov. 17, 1970 Th Be dixc i 1,926,628 9/1933 Morehouse..... 72/129 [73] Asslgnee 3,416,347 12/1968 Walsh et a1. 72/129 a corporation of Delaware Primary ExaminerRichard J. Herbst A tt0rneyGordon H. Chenez and Plante, Arens, Hanz, I-lix [54] METHOD OF SLITTING A CONTINUOUS STRIP OF and Smith METAL AND ARTICLE FORMED THEREFROM 10 Claims, 13 Drawing Figs. [52] us. c1 113/116,

72/129, 72/325 [51] Int. Cl. 821d 47/00 ABSTRACT: Method of slitting a continuous strip of steel of [50] Field of Search 113/1160, rectangular cross section and forming same to define a brakeshoe having an integral T-shaped cross section.

I i I L i J v 's :1 2 92 4- /6 291 if /3. 120

Patented Nov. 17, 1970 3,540,395 I INVENTOR. ROBERT L. SKINNER M a /VT METHOD OF SLITTING A CONTINUOUS STRIP OF METAL AND ARTICLE FORMED THEREFROM Various manufacturing procedures have been proposed to form a conventional arcuate drum brakeshoe of generally T- shaped cross-sectional area with attendant manufacturing time, labor and material held to a minimum which, by virtue of corresponding reduced manufacturing costs, is highly desirable particularly in the case of high volume production items such as automobile drum brakes. One such manufacturing method presently in use in high volume brake production of which I am aware includes stamping separate arcuate web and rim portions from sheet steel which are subsequently fixedly secured together in abutting relationship by a suitable welding operation thereby defining the desired arcuate brakeshoe having a T-shaped cross section. Obviously, such a two-piece brakeshoe includes a corresponding significant waste of sheet steel which coupled with the required weldingoperation for securing the same together is not entirely satisfactory. Furthermore, such a method of manufacture is not easily adapted to an automated sequence of operations thereby requiring significant material handling and machine operating labor.

It is an object of the present invention to provide a method of manufacturing a brakeshoe of T-shaped cross section having integral web and rim portions.

It is another object of the present invention to provide a method of slitting a continuous strip of metal of generally rectangular shaped cross section along one longitudinal edge thereof to form a generally T-shaped cross section having integral web and rim portions.

It is an important object of the present invention to provide an arcuate brakeshoe having a T-shaped cross section with integral web and rim portions.

Other objects and advantages of the present invention will be apparent from the following description taken with the accompanying drawings wherein:

FIG. 1 is a schematic representation of various machines embodying means for performing slitting and forming operations on a continuous strip of sheet steel.

FIG. 2 is a sectional view taken on line 2-2 of FIG. 1.

FIG. 3 is a sectional view taken on line 3-3 of FIG. 1.

FIG. 4 is a sectional view taken on line 44 of FIG. 1.

FIG. 5 is a sectional view taken on line 55 of FIG. I.

FIG. 6 is a sectional view taken on line 66 of FIG. 1.

FIG. 7 is a sectional view taken on line 7-7 of FIG. 1.

FIG. 8 represents a segment of T-shaped cross section cut from steel strip 22.

FIG. 9 represents the T-shaped segment of FIG. 8 after roll forming to define an arcuate brakeshoe.

FIG. 10 represents the arcuate brakeshoe of FIG. 9 after a trim and pierce operation on the web portion thereof.

FIG. 11 represents the brakeshoe of FIG. 10 after a final trim and pierce operation on the rim portion thereof.

FIG. 12 represents a view taken on line 12-12 of FIG. 1.

FIG. I3 represents a view taken on line 13-13 of FIG. 1.

Referring to FIG. 1, numeral 20 represents a conventional stock reel suitably supported for rotation about a fixed vertical axis A-A. A coil of flap strip steel generally indicated by 22 is horizontally supported by the upper flat surface of reel 20 and rotatable therewith about axis A-A. Preferably, the cross section of the steel strip takes the form of a rectangle having suitable width and length corresponding to the desired rim and web size of the T-shaped brakeshoe to be made therefrom in the following described manner.

Conventional machine apparatus 24 suitably modified to provide spaced-apart knurled surface feed rollers 26 and 28 as well as 30 and 32 are suitably mounted for rotation about associated vertical axes B-B. Motor driven drive mechanism, not shown, connected to rollers 26, 28 and 30, 32 drive the same in the direction indicated by the arrows associated therewith. A plurality of straightening rollers 34, 36, 38, 40 and 42 suitably arranged in spaced-apart relationship and mounted for free rotation about associated axes parallel to axes B-B. The strip of steel 22 is frictionally engaged by feed rollers 26, 28 and 30, 32 which drive the strip 22 through straightening rollers 34, 36, 38, 40 and 42 which, in turn, deform strip 22 to thereby eliminate the tendency for strip 22 to assume a curved shape as it is uncoiled from reel 20 and discharged from feed rollers 30 and 32. I

The straight strip of steel 22 is next received by conventional machine apparatus 44 suitably modified to provide progressive slitting and cutoff operations on steel strip 22. To that end, a base portion 46 is provided with a plurality of rotatable spindles 48, 50, 52, 54 and 56 journaled in fixed support members 57, 58, 60, 62 and 64, respectively, for rotation about parallel associated horizontal axes.

Each of the spindles 48, 50, 52,54 and 56 are provided with a gear or other suitable conventional driving mechanism, not shown, connected to be .driven by a motor, not shown, mounted in base portion 46. Circular slitting knives 68 and 70 suitably secured to spindles 48 and 50 and rotatable therewith are rotated in the direction indicated by the arrows. The circular slitting knives 68 and 70 have annular cutting surfaces of generally wedge-shaped cross section which vary in radial depth depending upon the desired depth of cut on steel strip 22. As shown, the radial depth of the annular cutting surface of knife 68 is significantly less than that of knife 70 to illustrate initial and final cutting steps performed on strip 22. However, it will be understood that additional knives similar to knives 68 and 70 but with varying radial cutting depth may be provided depending upon the characteristics of the metal from which strip 22 is made.

The spindles 52, 54 and 56 are provided with forming rollers 72, 74 and 76, respectively, suitably secured thereto and rotatable therewith in the direction indicated by the arrows. The annular forming surfaces of rollers 72, 74 and 76 are generally wedge shape in cross section with the apex'of the wedge rounded as shown. The included angle of the wedgeshaped forming surfaces of rollers 72, 74 and 76 increases in that order to a maximum of 180 on roller 76.

Each of the circular knives 68 and 70 as well as forming rollers 72, 74 and 76 are provided with an associated pair of spaced-apart feed rollers 78 and 80 having knurled surfaces adapted to frictionally engage steel strip 22 passing therebetween to thereby urge the same longitudinally as well as provide horizontal support thereto. A roller 82 suitably mounted below rollers 78 and 80 for free rotation about a fixed axis C-C is adapted to engage the lower surface of steel strip 22 thereby providing vertical support to the strip 22 in opposition to the downward force exerted by the associated slitting knife 68 or 70 or forming roller 72, 74, 76 pressing against strip 22.

The steel strip is urged longitudinally by feed rollers 78 and 80 into engagement with slitting knives 68 and 70 which slit the strip 22 edgewise in a progressively deeper fashion as shown in FIGS. 3 and 4 to define diverging rim or arm portions 84 and 86 of equal thickness integral with a web portion 88. It will be noted that the axial length of feed rollers 78 and 80 is determined by the depth of penetration of knives 68 and 70 associated therewith to provide lateral support over the web portion 88 only.

The diverging rim portions 84 and 86 are further spread apart angularly by forming rollers 72, 74 and 76 which bear against the longitudinally moving strip 22. The metal strip 22 isprevented from tearing at the apex of the slitting portion by the transverserounded section of forming rollers 72, 74 and 76 which ride along the apex as the diverging portions 84 and 86 are spread. As in the case of knives 68 and 70 heretofore described, the feed rollers 78 and 80 associated with forming rollers 72, 74 and 76 provide lateral support over the web portion 88 only.

Conventional so-called flying cutoff mechanism generally indicated by 90 includes a carriage 92 suitably mounted on base portion 46 and connected to motor mechanism, not shown, for reciprocal movement longitudinally relative to steel strip 22. Spaced apart shear members 94 and 96 between which steel strip 22 passes are adapted to move transversely into engagement with strip 22 simultaneously with movement of carriage 92 in the direction of travel of strip 22 to thereby sever a segment 97 of predetermined length from strip 22. Upon completion of the shearing operation, the shear members 94 and 96 are actuated transversely out of the path of strip 22 to permit subsequent translation of carriage 86 in a direction opposite to the direction of movement of strip 22 to thereby reposition shear members 94 and 96 for the next shearing operation. In this manner, the strip 22 moves continuously with automatic reciprocation of carriage 92 and shear members 94 and 96 carried by carriage 92 relative to strip 22 to sever the advancing strip 22 into segments 97 of predetermined length as indicated in FIG. 8.

The flying cutoff mechanism 90 discharges the segments to conventional article transfer apparatus generally indicated by 98 suitably modified to feed the segments in sequence to roll forming apparatus generally indicated by 100. The forming apparatus 100 includes a circular member 102 provided with an annular recess 104 of suitable width and radial depth to accommodate the web 88 and connected to be driven by motor mechanism, not shown, in the direction of the arrow associated therewith. The peripheral surfaces of circular member 102 are knurled and frictionally engage the rim portions 84 and 86 thereby carrying the T-shaped segment 97 into engagement with arcuately spaced-apart rollers 106, 108 and 110 roll against upper surface of rim portions 84 and 86 thereby deforming the same against circular member 102 resulting in a corresponding curvature of rim portion 84 and 86 as well as web portion 88 as indicated in FIG. 9.

The curved segment passes through roller 110 and is discharged to conventional article transfer apparatus generally indicated by 112 suitably modified to feed the curved segments in sequence to conventional stamping apparatus generally indicated by 114 which is suitably modified to perform a trim and pierce operation on web portion 88. To that end, the stamping apparatus 114 may include fixed and movable die members 116 and 118 mounted on a bed 120 and movable ram 122, respectively, and adapted to cooperate in the usual manner to trim and pierce web portion 88 as indicated in FIG. 10.

A final stamping operation is performed on the rim portions 84 and 86 to define completed brakeshoe 124 as indicated in FIG. 11 by conventional stamping apparatus generally indicated by 126 which performs a trim and pierce operation on rim portions 84 and 86. Preferably the trim and pierce operation takes the form ofa so-called fine flow process in which case the stamping apparatus 116 is a conventional machine identified as a fine blanking press which may be obtained through Stoffel Fine Flow Stampings, 150 Ferris Avenue, White Plains, N.Y., 10603. Details of the above identified fine flow" process'and machine for performing the same may be readily obtained from literature distributed by the abovementioned source.

It will be recognized that a drum brakeshoe formed in the above-described manner with integral web and rim portions is structurally stronger and therefore, safer in its intended environment than a two-piece brake wherein the web and rim portions are attached by mechanical means such as a weld.

Various changes or modifications in the above described method may be made without departing from the scope of applicant's invention. For instance, it will be recognized that the continuous strip of metal 22 may take a cross-sectional shape other than the rectangular shape described and may be slit and formed to provide various cross-sectional shapes different from the proposed T-shape. Also, it may be desirable to perform the slitting and forming operations in a sequence other than the preferred sequence shown and described. To that end, the slitting knives and forming rollers may be arranged in proper order to provide slitting, forming, slitting, etc., in the desired sequence.

lclaim:

1. A method of slitting a continuous strip of metal having a generally rectangular cross section to provide a longitudinally extending web portion and diverging arm portions integral therewith comprising the steps of:

providing a strip of sheet metal having a generally rectangular cross section;

providing slitting means having a cutting surface adapted to engage said strip of metal edgewise and penetrate the same to a predetermined depth thereby defining a longitudinally extending web portion and diverging arm portions integral therewith; and

advancing said strip of metal longitudinally into engagement with said slitting means to continuously slit said strip of metal edgewise to a predetermined depth.

2v A method of slitting a continuous strip of sheet metal as claimed in claim 1 and further including the forming step of:

providing forming means adapted to engage said diverging arm portions and deform same relative to said web portion; and

said strip of metal being continuously advanced longitudinally into engagement with said forming means following said slitting means to provide simultaneous slitting and forming.

3. A method of slitting and forming a continuous strip of sheet metal as claimed in claim 2 and further including the step of providing cutoff means adaptedto engage said strip of sheet metal following said forming operation and sever said strip into segments of predetermined length.

4. A method of slitting and forming a continuous strip of sheet metal as claimed in claim 2 wherein said slitting operation is performed in a series of sequential steps by said slitting means which includes a plurality of spaced-apart cutting knives adapted to sequentially engage and progressively slit said strip of steel to an increasing depth.

5. A method of slitting and forming a continuous strip of sheet metal as claimed in claim 2 wherein said forming operation is performedin a series of sequential steps by said forming means which includes a plurality of spaced-apart forming members adapted to sequentially engage'and progressively deform said arm portions relative to said web portion.

6. A method of slitting and forming a continuous strip of sheet metal as claimed in claim 2 wherein said strip of sheet metal is wound in coil form and wherein said strip of steel is continuously advanced by said last named means which includes straightening means adapted to unwind said coiled strip of steel and straighten the same longitudinally.

7. A method of slitting and forming a continuous strip of sheet metal to form a drum brakeshoe of predetermined length having a generally T-shaped cross section comprising the steps of:

providing a continuous strip of sheet metal having a rectangular cross section shape;

providing a slitting means having at least one cutting surface adapted to engage said strip of steel edgewise and penetrate the same to a predetermined depth thereby forming diverging arm portions of equal thickness integral with a web portion;

providing forming means adapted to engage said diverging arm portions and bend same relative to said web portion to define a rim portion extending at a right angle to said web portion;

providing cutoff means adapted to engage said strip of steel and sever same into segments of predetermined length; and

providing means adapted to engage each ofsaid segments of predetermined length and trim and pierce said rim and web portions thereof to form a completed drum brakeshoe of T-shaped cross section having integral rim and web portions.

8. A method of slitting and forming a continuous strip of sheet steel to form a drum brakeshoe as claimed in claim 7 and further including the step of providing second forming means adapted to engage each said segment of predetermined length and bend same longitudinally to arcuate form.

sheet metal as claimed in claim 2 wherein said forming operation is performed by said forming means which includes a circular forming member mounted for rotation and having a continuous generally wedge-shaped forming surface adapted to roll between said diverging arm portions and deform same accordingly. 

